1. Field of the Invention
The present invention relates to a nondestructive inspection apparatus that inspects a structure for internal defects by irradiating the structure to be inspected with infrared light, and more particularly, relates to a nondestructive inspection apparatus and an inspection system of a structure that automatically inspect the structure for internal defects over a wide range of the structure by irradiating the structure with heating infrared light while the nondestructive inspection apparatus moves along the structure to be inspected through the use of a self-running mechanism unit and measuring a variation in temperature of the structure due to the irradiation with infrared light.
2. Description of Related Art
Such a conventional apparatus for inspecting of a structure for an internal defect includes: an infrared light source that irradiates a structure with infrared light; an infrared light irradiation time controller that is connected to the infrared light source; an imaging unit that is connected to the infrared light irradiation time controller and that takes an image of the structure irradiated by the infrared light source; an image accumulating device that is connected to the imaging unit and that accumulates the images taken with the imaging unit; and an image analyzing device that is connected to the infrared light irradiation time controller and the image accumulating device, and that analyzes the images accumulated in the image accumulating device (for example, see Japanese Patent Application Laid-Open Publication No. 2001-201474).
However, in the internal defect inspection apparatus of the structure, disclosed in Japanese Patent Application Laid-Open Publication No. 2001-201474, for example, when the degradation of an internal wall surface of a tunnel, as a structure to be inspected, is inspected, at least the infrared light source and the imaging unit are mounted on a movable vehicle (carrier vehicle) and the inspection is carried out by irradiating the internal wall surface of the tunnel with infrared light from the infrared light source while driving the carrier vehicle to move at a constant speed in the tunnel. In this case, since the carrier vehicle runs in the tunnel, it may hinder the movement of other vehicles. In order to avoid this hindrance, a time zone in which the number of passing vehicles is small, such as night time, has to be selected or the frequency of performing the degradation inspection has to be lowered. In addition, since a driver of the carrier vehicle is necessary and an operator who makes the wide range of the internal wall surface of the tunnel irradiated with infrared light is also necessary in order to inspect the entire range of the internal wall surface of the tunnel, automatic inspection is not possible.
Therefore, the invention is made to solve this problem and an object of the invention is to provide a nondestructive inspection apparatus and an inspection system of a structure that automatically inspect the structure for internal defects over a wide range of the structure by irradiating the structure with heating infrared light while the nondestructive inspection apparatus moves along the structure to be inspected through the use of a self-running mechanism unit and measuring a variation in temperature of the structure due to the irradiation with infrared light.